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37 .Nd Capability mode system calls
45 .Fn cap_getmode "u_int *modep"
48 places the current process into capability mode, a mode of execution in which
49 processes may only issue system calls operating on file descriptors or
50 reading limited global system state.
51 Access to global name spaces, such as file system or IPC name spaces, is
53 If the process is already in a capability mode sandbox, the system call is a
55 Future process descendants create with
59 will be placed in capability mode from inception.
61 When combined with capabilities created with
64 may be used to create kernel-enforced sandboxes in which
65 appropriately-crafted applications or application components may be run.
68 returns a flag indicating whether or not the process is in a capability mode
71 Creating effective process sandboxes is a tricky process that involves
72 identifying the least possible rights required by the process and then
73 passing those rights into the process in a safe manner.
77 for why this is particularly tricky with UNIX file descriptors as the
78 canonical representation of a right.
81 should also be aware of other inherited rights, such as access to VM
82 resources, memory contents, and other process properties that should be
84 It is advisable to use
86 to create a runtime environment inside the sandbox that has as few implicitly
87 acquired rights as possible.
89 .Rv -std cap_enter cap_getmode
95 Support for capabilities and capabilities mode was developed as part of the
99 These functions and the capability facility were created by
100 .An "Robert N. M. Watson"
101 at the University of Cambridge Computer Laboratory with support from a grant